Kingi isn't the kind of name you'd typically expect to hear in UK stuff like those.Also, as the strong link to previous isn't Marvel or superheroes, what could it be?And does anyone remember watching a film where they come up with haikus?

You say the name 'Kingi' is a clue that it might not be a UK thing, but 'wanker' is a very British insult. So my guess is somewhere else they say 'wanker' like Australia or New Zealand, (maybe South Africa?). Definitely not America, unless they're doing a poor impression of a Brit or Aussie.

Correct, it's Hunt for the Wilderpeople! The director of that film, Taika Waititi, not only directed Thor 3 but also played the character that delivered the "Piss off, ghost!" quote. I recommend both films, along with two more of his, What We Do In The Shadows and Eagle Vs Shark.